At their first wedding gig, Jonathan Warren & The Billy Goats got into a fistfight with the groom’s father. It’s a story Warren is hesitant to share—band brawls are a rare occurrence—but it epitomizes the trio’s raucous sound, an irresistible musical stew that the group’s frontman describes as “progressive psychobilly folk grass.”

On October 15, the Boise-based band – which has been together since 2008 – will celebrate the release of their fourth album, On This Very Evening. Warren, who plays bass, harmonica, and banjo, drummer Andrew Smith, and classically trained cellist/guitarist/vocalist David Sather-Smith have an extensive arsenal of musical influences ranging from Charles Mingus to Frank Sinatra to Townes Van Zandt; those influences and more can be found on the thirteen diverse songs of On This Very Evening. Album closer “Honey Dear” was influenced by lyrics Sather-Smith found in a book of 1940s sheet music that was gathering dust at a thrift store. Songs were written on riverbanks (“Coin Toss”), on cross-country buses (“Greyhound”), and in the bottom of a bottle (“I’d Rather”); Warren found inspiration for “Angeline” in a dream, and “On the Hill,” a poignant tale of unrequited love, was written in the Ada County Jail.

Jonathan Warren & The Billy Goats recorded the vast majority of On This Very Evening live as a trio, adding other instruments and musicians at a later date. Those additional parts and roster of guest musicians were assembled in the band’s typically freewheeling fashion. They’d never heard trumpeter Landon Lemieux—a longtime fan of the band—play before they invited him to lay down tracks on “Rules Bending” and the Latin-tinged “Living Room.” Warren’s banjo parts on “She Gets the Blues” and “Quite Clearly” were the result of experimentation, and his harmonica part on “Angeline” was a last-minute addition to the song. Add it all up, and the result is front porch music from the boys next door – if you lived next to moonshine runners and midnight ramblers.

The band kicks off a lengthy tour on September 20 in Ketchum, Idaho. Along the way they’ll play with kindred spirits like The Earl Brothers and open for roots rockers Ha Ha Tonka at a can’t-miss show in Las Vegas on October 2. Call Jonathan Warren & The Billy Goats’ foot-stomping, heart-racing concerts “progressive psychobilly folk grass,” or “new-timey, post-retro, pre-apocalyptic, Southern Appalachian gypsy porch swing” (another Warrenism), but the best way to describe them is also the simplest: damn good.